The ecological-economic response of the fishery to mangrove restoration

Ecosystem restoration is promoted as a nature-based solution to support both ecosystems and livelihoods, yet evidence on how it reshapes local economic behaviour and wellbeing remain scarce. This study shows how ecological restoration can reshape livelihoods, markets, and consumption patterns in ways largely unanticipated by program designers.

This research studies the ecological-economic response of fisheries to mangrove restoration in over 5,000 planting sites in the Philippines. We exploit the staggered roll-out of the Philippines’ National Greening Program between 2011-2018, applying difference-in-differences methods to ecological, fishery, and household survey data. Planting sites accumulate measurable mangrove cover over time and temporarily suppress nearshore phytoplankton productivity, consistent with growing trees competing for macronutrients at the base of the marine food web. These changes have theoretically ambiguous effects on fishing effort and catch. Empirically, catch remains unchanged while effort increases, a pattern consistent with expanding mangrove habitats making fish harder to catch rather than raising fishery productivity. Higher fishing costs are passed through to consumers via higher market prices for fish, inducing entry into the fishery while leaving household fishing incomes unchanged. Households substitute away from the consumption of fish towards meat and eggs, resulting in greater dietary protein diversity, with effects concentrated among poorer households and extending to non-fishing households.

About Professor Charles Palmer

Prof. Charles Palmer is an environmental and development economist with over 20 years of experience in teaching and research on the economics of land-use change and forest management. Much of his research is focused on the design and evaluation of policy, particularly policies relevant to biodiversity conservation, climate change and sustainable development. The scope of previous and current work extends to Europe, Latin America, Sub-Saharan Africa and South-East Asia. After degrees from Oxford, UCL and Bonn, and a post-doc undertaken at ETH Zurich, Prof. Palmer has been a member of the faculty of the Department of Geography and Environment at the LSE since 2009. He is currently an Affiliate/Associate at the Grantham Research Institute on Climate Change and the Environment, the Global School of Sustainability, the Centre for Climate Change Economics and Policy, and a member of the scientific committee for the BIOdiversity and Economics for CONservation network (BIOECON).